Direct current (DC) offsets in the transmit baseband path of a radio frequency (RF) transceiver can degrade the error vector magnitude (EVM) performance as well as the carrier suppression performance associated with a transmitted signal. These DC offsets typically are present as a result of circuit level mismatches and process-related variations in the transmit baseband signal paths. Such DC offsets may arise from, for example, digital-to-analog converters (DACs), gain amplifiers and baseband analog filters.
In light of the signal processing difficulties introduced by DC offsets, a number of techniques have been developed to reduce the DC offset in a transmitted signal. These conventional techniques typically employ considerable additional circuitry in the form of analog baseband correction loops, high-precision RF power detector, or RF demodulator to correct for DC offsets, thereby increasing the complexity and cost of implementing DC offset calibration in RF transceiving systems. Accordingly, an improved technique for DC offset correction would be advantageous.